Various types of agricultural machinery employ belt conveyors to move particulate material such as grain or seeds from one location to another. A paddle belt conveyor has a plurality of paddles attached at intervals on one side of a conveyor belt.
The belt conveyor, whether it has paddles or not, may be powered by a power takeoff (PTO) from a tractor or other work vehicle, a gas engine or an electric motor coupled to belts and pulleys, chains and sprockets, or gear drives. A hydraulic drive may alternatively be used to drive the conveyor. The conveyor may run upwardly through a tubular enclosure from a hopper designed to receive the particulate material to a spout that is designed to discharge the material. Alternatively, the conveyor may be a flat-pan conveyor in which the conveyor runs upwardly through a rectangular enclosure. The belt conveyor typically includes a support frame, a hitch and wheels for towing although, in other cases, the conveyor may be rigidly mounted and thus requires no frame or wheels. These types of belt conveyor are commonly used in the agricultural industry to convey grain, seed or other particulate matter from the hopper to the spout such as, for example, in moving grain or seeds from or into a storage bin or to move seeds or grain from or into a storage tank of a vehicle.
Traditionally, to convey particulate matter to greater heights requires longer conveyors. Longer conveyors are usually more expensive, more difficult to maneuver and, when inclined, take up more space in a loading area. Belt slippage and tracking also tend to worsen with increased conveyor length.
Another issue with conveyors is the size and location of the drive system. Conventional drive systems for conveyors tend to be bulky and are designed to be connected to the conveyor at the hopper.
Typical paddle conveyors in use today are driven from the discharge end, by wrapping the belt approximately 180 degrees around a head roller. The friction between the head roller and the back surface of the belt provides the means of power transmission. Conveyors with this type of drive system are limited in their length and/or elevation due to belt slippage.
S-shaped drive systems are used with smooth (non-paddle) belts to increase power transmission by increasing the contact area between the belt and the drive roller (i.e. using a larger drive roller and/or increased angle of belt wrap). An S-drive also allows for the placement of the power source (PTO, gas motor, electric motor, etc.) at a more convenient operating position than the elevated discharge end of the conveyor.
Applicant has recognized that it would be advantageous to provide an S-shaped drive system for a paddle belt conveyor. Developing an S-shaped drive system for paddle belts proved to be a significant technical challenge because a traditional S-shaped drive has rollers which contact both sides of the belt. Accordingly, Applicant realized that a means had to be developed to allow the paddles to pass through the drive, while still providing for sustained contact with both top and bottom surfaces of the conveyor belt. In developing a design for a paddle belt S-drive, other ideas were first tried. One such concept tested by Applicant had a drive roller with slotted openings. The slots were timed with the paddle spacing on the conveyor belt so that the paddles could pass radially inwardly through the driving/contact surface of the drive roller. This concept had limitations because if the belt slipped, or if the belt stretched, the timing would be disrupted causing the paddles and driving surface of the roller to come in contact.
Accordingly, it would be highly desirable to provide an efficient and compact drive system, whether having an S shape or not, for use with a paddle belt conveyor.